*{padding: 0;margin: 0;}
ul.li{list-style: none;}

.myheader{
  width: 100%;
  height: 150px;
  background: lightgreen;
}
.myfooter{
  width: 100%;
  height: 50px;
  background: lightgreen;
  position: fixed;
  bottom: 0;left: 0;right: 0;
}
.conitem{display: flex;}
.red{background: #f03d37;color: #fff;}
.red{background: #3c9fe6;color: #fff;}